Re: [PATCH] New x86_64 EFI patch

[Robert Millan <rmh@aybabtu.com>]

On Sat, Jul 12, 2008 at 11:16:31PM +0800, Bean wrote:
> On Sat, Jul 12, 2008 at 10:41 PM, Robert Millan <rmh@aybabtu.com> wrote:
> > On Wed, Jul 09, 2008 at 12:31:53AM +0800, Bean wrote:
> >> > -- I tried passing video=intelfb to linux; it worked under grub2-pc but
> >> > didn't improve anything under efi.
> >>
> >> intelfb doesn't work. The only way to see console in efi is to use
> >> video=vesafb or video=efifb.
> >
> > How come?  I thought intelfb used the bare hardware.
> 
> The video register in efi mode is not setup in the same way as bios.
> There are two sets of register. In EFI, set A is completely zero,
> while set B have non-zero value. But in bios mode, both set have
> non-zero value. I guess this is because bios have text and graphic
> mode, while efi only have graphic mode. (text mode in efi is emulated)

But isn't intelfb supposed to access the hardware without any support
from bios/vesa or efi?

-- 
Robert Millan

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